Greenback
Active member
Sounds like crappy plastic then to me, They were likely under tension internally due to the design hence why they are cracking/cracked at the same points.
I notice the inside ring has split at the seam on the right one and the left has a seam split above the front trigger, just looking on net I found posts of people with similar cracks, so seem a design flaw.
If they don't replace them then I could probably get some proper tamiya cement glue and fix them